Tipping your bartender.

Tipping 20% on drinks is standard unless you are getting a bottle of water.  If you don't give a dollar minimum per drink, and $2 for more expensive, or difficult to make drinks, then you shouldn't go out.  Even if you are the DJ, Promoter, or other staff member of the event, you need to be tipping.  I don't give a shit if you have four drink tickets, you still need to tip you cheap bastard!  If you are too broke to tip, and you are spending the last of your money on some party, then you are a dumb ass.  Stay the fuck home and work on your shitty life, because you obviously have bigger problems, and a simple night out won't fix that.

Most bartenders make minimum wage and that alone isn't enough for how expensive it is to live in SF, so they count on those tips.  Plus they have to deal with drunk dipshits all the time, and they just stand there smiling while people scream their stupid boring stories in their ear.  They get hit on all the time by bragging egotistical douche bags talking about their start up company and whiskey collection.  They have to memorize hundreds of drink combinations, while dozens of people yell at them all night to serve them next.  They have to listen to all sorts of horrible music that they never listen to at home, and they don't get off til after 3 in the morning.  It's not an easy job, so show some respect like you do to servers in a restaurant.

Anyhow, here is a youtube video I found on tipping that seems pretty accurate: